Hashcode and Frequency API

import java.lang.Math;
import java.util.*;

public class HelloWorld
{
  public static void main(String[] args)
  {
   Set set = new HashSet();
    Num n = new Num(2);
 
    Num n1 = new Num(2);
  /*  set.add(n);
    set.add(n);
    System.out.println(set.size()); //1*/
 
      set.add(n);
    set.add(n1);
    System.out.println(set.size()); //2
 
    System.out.println(n.hashCode()); //1829164700
  System.out.println(n1.hashCode()); //2018699554
 
    System.out.println(Collections.frequency(set,n)); //1
 
    // create array list object    
   List arrlist = new ArrayList();
   
   // populate the list
   arrlist.add("A");
   arrlist.add("B");
   arrlist.add("C");
   arrlist.add("C");
   arrlist.add("C");    
         
   // check frequensy of 'C'
   int freq = Collections.frequency(arrlist, "C");
   
   System.out.println("Frequency of 'C' is: "+freq);
    System.out.println(arrlist.size());
    for(String x : arrlist){System.out.println(x.hashCode());}
 
  }
}
// this will become its own file too (and these can be in any order)
public class Num
{

  private int x;
 Num(int x){
   this.x=x;
   }

}

2
1829164700
2018699554
1
Frequency of 'C' is: 3
5
65
66
67
67

 List ll = new ArrayList();
        ll.add("one");
        ll.add("two");
        ll.add("three");
        ll.add("four");
        ll.add("two");
        ll.add("three");
        ll.add("two");
        ll.add("one");
        System.out.println("Actual list: "+ll);
        System.out.println("Frequency of 'one': "+Collections.frequency(ll, "one"));
        System.out.println("Frequency of 'three': "+Collections.frequency(ll, "three"));
        System.out.println("Frequency of 'two': "+Collections.frequency(ll, "two"));